| → draw the line for others, 1866 |
| determine for others, 1869 |
| determine for another, 1872 |
|
| → and determine with certainly 1866 |
| OMIT 1869 1872 |
|
| → to call varieties 1866 |
| ought to be called species 1869 1872 |
|
| → to call species. 1866 |
| varieties. 1869 1872 |
|
| ↑ 1 blocks not present in 1859 1860 1861 1866; present in 1869 1872 |
| Mr. Walsh ranks the forms which it may be supposed would freely intercross
together,
as varieties; and those which appear to have lost this power, as species.
|
|
| → in all these cases clearly 1866 |
| OMIT 1869 1872 |
|
| → intermediate links between the several forms thus produced 1866 |
| it 1869 1872 |
|
| → to 1866 |
| that intermediate links connecting the several forms should now 1869 1872 |
|
| → of doubtful value, 1866 |
| OMIT 1869 1872 |
|
| → But when 1866 |
| When, on the other hand, 1869 1872 |
|
| → chance, which is not rarely successful, 1866 |
| good chance 1869 1872 |
|
| → go so far as to 1866 |
| OMIT 1869 1872 |
|
|
can
→draw the line for others,
even if he can do so for himself,
→and determine with certainly
which of
forms
→to call varieties
and which
→to call species. Mr. Walsh, who argues with much force that the different states have gradually passed into each other, is forced to assume that those forms, which it may be supposed would freely intercross, should be designated as varieties, whilst those which have probably lost this capacity for intercrossing should be called species. ↑
As the
→in all these cases clearly
on the insects having long fed on
distinct plants,
→intermediate links between the several forms thus produced
cannot be expected
→to
be
The naturalist thus loses his best guide in determining whether to rank
doubtful forms as varieties or species. This likewise necessarily occurs with closely allied organisms,
→of doubtful value,
which inhabit
continents or
islands.
→But when
an animal or plant ranges over the same
or inhabits many islands in the same archipelago, and presents different forms in the different areas, there is always a
→chance, which is not rarely successful,
that intermediate forms
be discovered which
link together the extreme states; and these are then degraded to the rank of varieties. |
|
| Some few naturalists maintain that animals never present varieties; but then these same naturalists rank the slightest
as of specific value; and when
the
form is met with in two
countries, or in two
geological formations, they
→go so far as to
believe that two
species are hidden under the same dress. The term species thus comes to be a mere useless
abstraction, implying
|
